School: Chronomancy (Divination)
(Intended for use with the Chronomancer subclass)
The caster is able to determine approximately how old a specific non-living object, item, or material is. This could be a small statue, furniture, weapon, food, etc. If used on the dead remains of a lifeform, the results will indicate how long it has been dead. Immediately, the caster gains a sense for eras: Current age, some previous age, future age. The DM determines what constitutes an "age" in that reality. If concentration is held for an entire round, the estimation becomes accurate to the century. For the next level of accuracy, the target item must be touched at some point. As concentration is held approaching 1 minute, age of the item can be known with accuracy somewhere between 1 decade and 1 year.
For higher accuracy, the item must be touched, and contact with it maintained for the entire duration of the spell. If touched or held for the full 5 minutes, accuracy may be possible in terms of months.
The degree of accuracy possible, regardless of how long concentration is maintained, is always determined by the DM. Some items may simply be too hard (or perhaps too powerful) to estimate at scales smaller than centuries, for example. On the other hand, some items may be trivial to determine, and accuracy to the day (or even hour) might be possible, perhaps even without the full 5 minutes of concentration.
This spell is an original work.
A full list of 50+ Chronomancy spells, plus related monsters, items, backgrounds, etc, can be found in the comments of my Chronomancer (Wizard) subclass here.
https://www.dndbeyond.com/subclasses/6582-chronomancer
Chronomancer, Version 2 - [https://www.dndbeyond.com/subclasses/522102-chronomancer]